Bleach activators in granular form

ABSTRACT

A process for preparing free-flowing granules containing a bleach activator and a substantially water-free binder for the bleach activator. The process consists essentially of premixing a mixture of anionic and nonionic surfactants and the bleach activator, homogenizing the resulting mixture to form a paste which is extrudable in strand form, extruding the paste under elevated pressure, and cutting the extrudate into granules.

BACKGROUND OF THE INVENTION Field of the Invention

This invention relates to new pourable and free-flowing granulescontaining bleach activators for washing laundry in a binder phase astheir principal constituent, the binder phase predominantly containingsurfactants which are solid at room temperatures and moderately elevatedtemperatures, for example up to about 40° C. The invention also relatesto a process for the production of the new bleach activator granules.

Inorganic peroxy compounds which dissolve in water with release ofhydrogen peroxide, such as sodium perborate and sodium peroxycarbonate,have long been used as oxidizing agents for disinfection and bleachingpurposes. The oxidizing effect of these substances in dilute solutionsis governed to a large extent by temperature. Thus, with perborate inalkaline bleach liquors, sufficiently rapid bleaching of soiled textilesis only achieved at temperatures above 60° C. At lower temperatures, theoxidizing effect of the inorganic per compounds can be improved byaddition of activators for which numerous proposals have been publishedin the literature. The addition of these activators can increase thebleaching effect of aqueous peroxide solutions to such an extent thatthey are active at temperatures of only 30° to 60° C., i.e. at thetemperatures required for the washing of delicate fabrics.

However, these activators, for example from the class of N- and O-acylcompounds, are highly sensitive to hydrolysis, above all in the presenceof the alkaline ingredients typically used in detergents. The resultingproblems for the stability of the laundry detergents in storage areaggravated by the fact that the activators are often poorly soluble inwater so that very fine-particle materials with rapid dispersibilityshould be used. However, this fineparticle form promotes greaterhydrolysis of the activators in storage on account of the increasedsurface.

Discussion of Related Art

In practice, the situation is remedied by adding the bleach activator tothe dry detergent mixtures in the form of separately produced granules,the agglomerates of fine bleach particles being coated with auxiliaries.Various organic and inorganic substances have been proposed asgranulation aids and coating materials for such activator granules. Moreparticularly, the use of surfactant compounds solid at room temperaturefrom the classes of anionic, cationic and/or nonionic surfactants,polymeric materials or waxes is well known. Thus, European patentapplication EP 37 026 (Henkel) describes the production of pourable,uniformly coated bleach activator granules containing more than 90%active substance. In this process, 90 to 98% by weight of a powder-formbleach activator from the class of N-acylated amines, amides,diketopiperazines and glycolurils are mixed with 10 to 2% by weight of apowder-form granulation aid. The dry premix is then moistened with anaqueous solution of the granulation aid, after which the mixture isgranulated. The moist granules are then dried to low residual watercontents. The granulation aids used are, in particular, water-solublecellulose ethers, water-soluble starch or water-soluble starch ethers.

Referring first to the prior art, European patent application EP 6 655(P & G) describes the use of organic solids melting at 30° to 60° C. asagglomeration aids for the production of bleach activator granules andthen discusses in detail the use of nonionic surfactant compounds fromthe class of linear or branched C₁₀₋₂₄ fatty alcohol ethoxylates, theclass of C₈₋₁₈ alkylphenol ethoxylates or polyethylene glycols havingrelative molecular weights above 4000 as granulation aids. The alcoholethoxylates are compounds which are solid under normal conditions andcontain at least 15 EO groups per mol alcohol, the use of correspondingcomponents containing approximately 20 EO groups being preferred. Thesesolid nonionic surfactants may be used together with liquid orpaste-form nonionics having a relatively low degree of ethoxylation. Thegranule mixture is said in particular to contain 30 to 50% by weightactivator to 50 to 70% by weight of the nonionic compound(s). Themixture is prepared by melting of the nonionic compound, incorporationof the fine-particle activator and subsequent extrusion to a sphericalmass from which spherical particles can ultimately be obtained.Powder-form organic or inorganic mixing components, such as urea,polymer compounds, silica, talcum, smectite clays, fine-particlezeolites or inorganic water-soluble salts, may be used.

According to European patent application EP 106 634 (P & G), mixtures ofanionic surfactants, for example fatty acids, together with nonionicsurfactants are used as granulation aids for binding the fine-particleactivator components. It is pointed out with regard to the mixtures inquestion that comparatively small quantities of the binder aresufficient to provide the granules with the required combination ofproperties, namely stability in storage, strength and, at the same time,rapid dissolution in practical application. It is stated that theanionic surfactants used as fatty acids presumably reduce thehygroscopic effect of the nonionic binder while, on the other hand, thenonionic binder improves the dispersibility of the fatty acids or theother anionic surfactants. Three different methods of forming activatorgranules using these binder mixtures are investigated, the highestdegree of retention of bleaching activity being achieved by extrusionand subsequent granulation. Activator/surfactant mixtures to whichconsiderable quantities of water have been added to establish a state ofplastic processability are used throughout as the multicomponent mixtureto be extruded. Accordingly, the granules initially formed have to besubjected to a drying treatment to remove the added water.

European patent application EP 75 818 (BASF) is concerned withgranulation processes in which the bleach activator granules areprepared using water as one of the auxiliaries. It has been found that,even after drying, the corresponding activator granules arecomparatively sensitive to temperature and hydrolysis -- obviously as aresult of the added water. A small quantity of the water used as agranulation aid always remains behind in the granules and immediatelydestroys part of the stabilization which the granulation process isintended to provide. According to the disclosure of this patentapplication, the formulation of bleach activators pursues twoobjectives. Firstly, there is a need to improve the hydrolysis stabilityof the activators which, irrespective of the chemical individual, allhave a readily saponifiable active group which has to be protectedduring storage in the alkaline washing powder. Secondly, any suitablemethod for protecting the bleach activator from its surroundings mustallow rapid dispersion of the activator in the wash liquor. The teachingof this patent application addresses the problem of providing -- withoutwater and without using readily water-soluble highly hydratablecompounds -- activator granules which have a small inner surface, fromwhich no residual water has to be evaporated and which, nevertheless,can be spontaneously dispersed in the wash liquor and achieve distinctlybetter stability in storage. To solve this problem, it is proposed toprocess the bleach activators with small quantities of a water-swellableauxiliary by dry compacting between two rollers without using water. Itis specifically pointed out that the conventional methods of pelletizingand roll-up granulation are unsuccessful. The dry mixture is compressedin the gap between the rollers and the sheet formed is size-reduced.

Finally, European patent application EP 373 743 (Clorox) proposes usingfor granulation organic binders which have melting points above about40° C. and, more particularly, above about 50° C. and which do not reactwith the activators or any other auxiliaries used. Surfactant compoundsfrom the classes of nonionic, anionic and cationic surfactants arementioned along with film-forming polymers, selected relativelylong-chain aliphatic alcohols, comparatively low molecular weightpolyethylene glycols, starch, starch ethers and carboxymethyl celluloseand many other auxiliaries of synthetic and/or natural origin. Forgranulation, the auxiliaries are processed in the presence of water to apaste-like consistency. After incorporation of the activator, thedough-like mass formed is extruded, dried in noodle form andsubsequently reduced to granules. The water required as plasticizingagent or solvent may be added as external water, although it is alsopossible to introduce the water required into the process at leastpartly through the auxiliaries to be used, for example in the form of anaqueous anionic surfactant paste. Accordingly, the process described inthis document for the formation of granules from the fine-particlebleach activators reintroduces the problem with which EP 75 818 citedabove was concerned and, to solve that problem, proposes forminganhydrous mixtures in the gap between rollers with subsequentsize-reduction of the compressed material.

The problem addressed by the present invention was to provide granulesof fine-particle activators without having to use water as a temporaryliquid phase. The stability of the granules in storage would beguaranteed, even without intermediate drying and in admixture withtypical detergent ingredients, although at the same time the rapiddispersion of the bleach activator granules in the detergent solutionwould be ensured in practical application.

Description of the Invention

Other than in the operating examples, or where otherwise indicated, allnumbers expressing quantities of ingredients or reaction conditions usedherein are to be understood as modified in all instances by the term"about".

In a first embodiment, therefore, the present invention relates topourable and free-flowing granules containing bleach activators for thewashing of laundry and a substantially water-free binder phase of amixture of anionic and nonionic surfactant compounds, the binder phaseconsisting predominantly of substances which are solid under typicalstorage conditions. It is crucial to the teaching according to theinvention that the binder phase should consist of a homogenized mixtureof surfactant compounds of which the components are at least partlyliquid or at least plasticized at the granulation temperature and areadapted to one another in their respective quantities so that the binderphase is liquid or soft and plastic, even without water, at the workinggranulation temperature.

In another embodiment, the present invention relates to a process forthe production of the bleach activator granules which is characterizedin that the fine-particle bleach activators are mixed with thesurfactant components, the resulting mixture is homogenized atpreferably moderately elevated temperatures to form a paste extrudablein strand form and the paste thus formed is extruded in strand formunder elevated pressures, the issuing strands are cut into granules andoptionally rounded under process conditions which prevent the freshlyextruded material from sticking.

In one particularly important aspect, the teaching of the invention ischaracterized by the choice and co-use of washing-active surfactantcomponents which are capable of performing a binder function during thehomogenization step and which ensure the processability of the mixturein an extrusion process, effectively protect the granules formed and thefine-particle activator encapsulated by the binder against unwantedinteraction with moisture and other detergent ingredients, but at thesame time ultimately ensure the rapid dispersion of the grain structurein the aqueous liquor.

A preferred embodiment of the invention is characterized by the use of abinder phase which is solid at room temperature and which consists of amixture of washing-active surfactants of which the components are partlysolid at the typically elevated granulation temperature and, for therest, are liquid or at least soft and paste-like. It may be preferableto use surface-active liquid components or surfactant components whichsoften into a paste at the working granulation temperature and whichshow the corresponding rheological behavior, even at room temperature,i.e. are again present as a liquid phase or as a plasticized paste-likephase.

The homogenized mixture of solid surfactants and liquid or plasticsurfactant components should retain its preferably solid and alsonon-tacky structure not only at room temperature, but also at themoderately elevated temperatures encountered in the practical handlingof the active substances or mixtures in question. In practice, thismeans that the surfactant mixture preferably used as binder should havethe character of a solid up to upper temperature limits of about 35° to40° C. Granulation takes place at higher temperatures, although uppertemperature limits are rapidly reached in this case, too, on account ofthe well-known temperature sensitivity of bleach activators. In general,the working granulation temperature does not exceed 90° C., preferably80° C. Working granulation temperatures in the range from about 45° to70° C. can be particularly suitable. The working granulation temperatureis the temperature which can be externally adjusted by heating orcooling. By contrast, the granulation temperature is the temperature atwhich the granules are actually formed. Hitherto, this temperature hasnot been measured for reasons associated with machine construction.Accordingly, the temperatures mentioned in connection with granulationare always working temperatures. It may be assumed that, under theparticular process conditions prevailing, the granulation temperature isgenerally above the working temperature and is only identical with theworking temperature in exceptional cases.

Accordingly, the teaching according to the invention proposes usingbinders based on surfactants and, more particularly, on mixtures ofanionic and nonionic surfactants, preferably mixtures which are solid upto 40° C., but which -- as a softening and plasticizing component in thehigher permitted temperature range up to 90° C. -- enable the mixture tobe homogenized and the surfactant mixture to be thoroughly distributedin the activator mixture with simultaneous coating of the individualbleach activator particles. The mixture which is plasticized at theseelevated working temperatures is preferably extruded in strand-form andcut into granules by methods known per se. All that now remains is tocool at least the outer surface of the granules sufficiently quickly toprevent them from adhering o to one another. There is no longer any needfor drying in the conventional sense to remove water because thegranules only contain small negligible quantities of water which isintroduced by the raw materials used, but preferably no additional waterwhich would be necessary as an auxiliary granulation liquid. However, itcan be of advantage for another reason additionally to introduce waterin quantities of up to 1% by weight, based on the bleach activatorgranules. This reason will be discussed in more detail hereinafter.Apart from this preferred variant described o hereinafter, the processis preferably carried out with no addition of water. The desired optimalprotective function of the binder is directly developed in the granules.In a preferred embodiment of the invention, the anionic surfactantcomponent may be selected as the larger component of the surfactantmixture. In this case, it is particularly preferred to use correspondinganionic surfactant compounds which are solid at room temperature and atthe working granulation temperature and which may make up at least 55%by weight and up to 98% by weight of the surfactant mixture forming thebinder. The anionic surfactant content of these anionic surfactantssolid at room temperature and at the working temperature is best in therange from 60 to 95% by weight and more particularly in the range from60 to 85% by weight, based on the weight of the surfactant mixture.

Suitable solid anionic surfactants are the solid components known indetergent technology, more particularly in the context of laundrydetergents, which belong in particular to the following classes: alkylsulfates, alkyl sulfonates, alkylaryl sulfonates, sulfonated fatty acidesters and/or soaps. Particularly suitable anionic surfactants are, forexample, C₁₂₋₁₈ fatty alcohol sulfates which may be present individuallyor in admixture, such as lauryl sulfate, myristyl sulfate and, moreparticularly, C₁₆₋₁₈ tallow alcohol sulfate. Other suitable specialanionic surfactant components are C₉₋₁₃ alkylbenzene sulfonates (ABS),more particularly C₁₂ alkylbenzene sulfonate, washing-active salts ofα-sulfonated fatty acid methyl esters and/or sodium soaps of fattyacids, more particularly C₁₂₋₂₀ fatty acids. In this case, too, theplasticizability of the binder mixture at the elevated workingtemperatures can be influenced by the co-use of unsaturated componentsand/or by the use of potassium soaps.

Particularly suitable liquid surfactant mixture components forformulating the surfactant mixture acting as plasticizing agent and alsoas binder in accordance with the invention are nonionic surfactant fattyalcohol ethoxylates, i.e. preferably corresponding compounds based onC₁₂₋₁₈ fatty alcohols. In important embodiments, the average degree ofethoxylation does not exceed, or does not significantly exceed, a valueof 10, corresponding nonionic surfactants having lower degrees ofethoxylation being preferred. It is known that nonionic surfactants ofthe type in question are mixtures both in regard to their fatty alcoholbase and in regard to the degree of ethoxylation, the rheology or ratherthe dependence on temperature of the rheology of these mixtures beingvariable through the choice of the mixtures. A preferred limit to theaverage EO value is 7, corresponding compounds fluid even at roomtemperature with EO values of about 3 to 5 being particularly preferred.

The most important embodiment of the invention is characterized by theuse of anionic surfactant/nonionic surfactant mixtures which are highlyeffective plasticizers at the working granulation temperature so thatthe desired plasticized consistency of the activator mixture can beestablished with only limited quantities of the surface-active binder.In this embodiment, the surfactants are present in quantities ofpreferably less than about 50% by weight, based on the mixture as awhole, while the bleach activator is preferably present in the mixtureas a whole in quantities of from about 70 to 95% by weight. Theremainder of each granule is formed by the surface-active binder or atleast to a substantial extent by the surface-active binder. In importantembodiments, the granules contain at least about 3% by weight andpreferably at least about 5% by weight of the surface-active binder orbinder mixture, quantities of the surface-active binder phase of fromabout 7 to 20% by weight being particularly preferred.

The free-flowing, substantially water-free compactates directlyaccumulating in the process may contain as fine-particle bleachactivators any of the substances or mixtures of substances presentlyknown for this purpose. In the interests of completeness, the substancesin question are summarized once more as follows: suitable bleachactivators for per compounds are O- and/or N-acylated compounds, such aspentaacetyl glucose (PAG), pentapropionyl glucose (PPG), tetraacetylethylenediamine (TAED), tetraacetyl glycoluril (TAGU), triacetylethanolamine (TAEA), acylated triazine derivatives, such as1,5-diacetyl-2,4-dioxohexahydro-1,3,5-triazine (DADHT) or1,3,5-tris-(dimethylaminopropyl)-perhydro-1,3,5-triazine, carboxylicanhydrides, such as succinic, benzoic or phthalic anhydride, salts ofmixed anhydrides, such as sodium or magnesium diacetyl phosphate (NADAPor MGDAP), phenol esters, such as p-carboxyphenyl acetate, p-sulfonylphenyl acetate, p-cresyl acetate or phenyl acetate and other phenolesters present with an anionic substituent at the phenyl group. Inaddition to the above-cited publications concerned with correspondingbleach activators, the following relevant publications are alsomentioned: DE 30 11 998, 38 07 920 and 38 07 921 and EP 98 021. In thecontext of the invention, fine-particle bleach activators are understoodto be activator particles of which the maximum particle size isgenerally not above 500 μm and preferably not above 350 μm (Helosparticle size analysis). A particularly advantageous distribution is onein which at least 90% of the particles have a size of at most 250 μmand, more particularly, in the range from 50 to 200 μm.

In one particular embodiment, the process according to the invention forthe production of the bleach activator granules is characterized in thatthe multicomponent mixture is first homogenized in a suitable mixereither at room temperature or at only moderately elevated temperatures.Suitable mixers are any of the machines typically used for this purpose,for example of the Lodige plowshare mixer type. This premix is thenhomogenized and processed in strand-like form. Although, basically, anytype of extruder, for example linear screw extruders, may be used forthis purpose, the choice of a processing machine has proved toparticularly suitable for carrying out the process according to theinvention. The machine in question is a strand-form pellet press. It canbe of advantage in this regard to use corresponding machines with atemperaturecontrolled pressure roller of the type described in detail inDE 38 16 842. By means of this temperature-controlled pressure roller,the temperature in the working zone of the pellet press can be adjustedto predetermined values, the above-mentioned working temperature rangeof up to at most 90° C. and preferably from 45° to 70° C. beingselected.

If necessary, the granules are subjected to shockcooling. Cooled air maybe used as the cooling medium for this purpose. In addition oralternatively, the initially extruded and cut granules may besurface-treated with fineparticle solids, of which examples arepowder-form zeolites, more particularly zeolite NaA of detergentquality, talcum, silica and the like.

It may be desirable and/or appropriate to incorporate other auxiliariesin the granules in addition to the bleach activators and thesurface-active binder or binder mixture. These other auxiliariespreferably make up no more than 10% by weight of the granules. Suitableother auxiliaries are, for example, dyes which are known to the experton detergents. It may be useful to suspend or dissolve these componentsin the liquid surfactant component before it is incorporated in thepremix. Preferred dyes are pigment dyes, such as copper phthalocyaninedyes. To enhance the coloring effect of the pigments, water is added tothe liquid surfactant component in quantities of up to at most 1% byweight and preferably 0.1 to 0.5% by weight, based on the bleachactivator granules according to the invention. However, otherauxiliaries, for example disintegrating agents, water-soluble salts andthe like may also be used in order to bring out certain properties ofthe final granules. The prior art literature cited at the beginning maybe consulted in this regard as to the type of bleach activator granulesin question here.

In the extrusion of the multicomponent mixture heated to the workingtemperature, compression ratios may be established to provide the finalgranules with apparent densities of at least 500 g/l. Apparent densitiesof up to 1000 g/l are suitable, apparent densities in the range from 600to 900 g/l being particularly preferred. Depending on the properties ofthe mixture, virtually any desired density range may be specificallyestablished in the granules through the choice of the predeterminedextrusion pressures and other processing conditions.

The granules produced in accordance with the invention are preferablycylindrical or spherical in shape. Additional rounding may usefully becarried out immediately after cutting of the strands, i.e. before thegranules have completely cooled and are still sufficiently warm.Machines suitable for rounding are known and include, for example, theMarumerizers used for this purpose.

The particle size of the granules is controlled in known manner and isbest adjusted to values in the range from 0.7 to 3 mm. For example, thegranules can be formed in the required length of 0.7 to 3 mm or longer,for example in a length of 5 mm. The cylindrical granules with lengthsof more than 3 mm are subsequently broken to a predetermined length andoptionally rounded so that a length of 3 mm is not exceeded. Cylindricalgranules preferably have a length of up to 3 mm while preferredspherical and optionally rounded granules have a particle diameter of 1mm to 2 mm.

EXAMPLES

To produce the granular bleach activators, components (A) to (D), ofwhich (A), (B) and (D) were solid or in powder form and (C) was liquid,were intensively mixed for 1 minute in the ratios shown in the Table ina Lodige plowshare mixer (manufacturer: Lodige, Germany). The particlesize of the bleach activators (a) was less than 300 μm (Helos particlesize analysis). In the case of (A1), TAED, more than 90% of theparticles were below 170 μm in size. The premix thus obtained was thenfed continuously to an annular die press (pellet press according to DE38 16 842, manufacturer: Schluter, Germany) of which thetemperaturecontrolled pressure roller had been heated to 50° C. Slightvariations in temperature occurred during the process, the temperatureof the pressure roller remaining above 45° C. and below 60° C. Thediameter of the bores permeating the annular die was 1 mm to 1.5 mm (seeTable). The interval between the pressure roller and the annular die was1.8 mm to 3 mm (see Table). The strand issuing from the die was cut to alength of 1.5 mm by a knife arranged on the outside. In addition, thegranules of Examples 1 and 7 were rounded in a commercially availablemachine of the Marumerizer type. Since all the products were tack-free,it was not absolutely essential to cover the surface of the granuleswith a solid, such as zeolite NaA.

The low-dust products 1 to 7 were sieved through 0.6 mm and 1.6 mm meshsieves. In every case, the fine component of the granules smaller than0.6 mm in size was at most 2% while the coarse component of the granuleslarger than 1.6 mm in size was at most 1%. The sieved products had anapparent density of 650 g/l to 820 g/l.

                                      TABLE                                       __________________________________________________________________________                              1   2   3   4   5   6   7                           __________________________________________________________________________    Composition in % by weight:                                                   (A)                                                                              Bleach activator                                                           (A1)  TAED                80  80  --  85  --  90  --                          (A2)  DADHT               --  --  80  --  85  --  90                          (B)                                                                              Anionic surfactants                                                        (B1)  Sodium dodecylbenzene sulfonate (96%)                                                             8.0 8.5 7.5 10  7   8   7                           (B2)  C.sub.16-18 tallow alcohol sulfate                                                                4.0 5.5 4.0 --  3   --  --                          (B3)  C.sub.12-18 sodium fatty acid soap                                                                --  --  0.5 --  --  --  --                          (C)                                                                              Nonionic surfactants                                                       (C1)  C.sub.12-18 fatty alcohol · 5 EO                                                         6.0 --  5.0 --  --  --  3                           (C2)  80% C.sub.12-18 fatty alcohol · 5 EO                                                     --  6.0 --  --  3   2   --                                20% C.sub.12-14 fatty alcohol · 3 EO                           (C3)  C.sub.12-18 fatty alcohol · 7 EO                                                         --  --  1.0 5.0 2   --  --                          (D)                                                                              Zeolite NaA            2.0 --  2.0 --  --  --  --                          Diameter of the die bores (in mm)                                                                       1.5 1.0 1.0 1.5 1.5 1.0 1.0                         Pressue roller/die interval (in mm)                                                                     3.0 2.0 1.8 2.0 2.0 2.8 2.0                         Yield of 0.6 mm-1.6 mm granules                                                                         97  97  97  97  97  97  97                          at least (in %)                                                               Apparent density of granules (in g/l)                                                                   820 680 650 700 710 750 690                         __________________________________________________________________________

We claim:
 1. A composition comprising free-flowing granules containingfrom about 70 to about 95% by weight of a bleach activator, based on theweight of said granules, and a substantially water-free binder for saidbleach activator, said binder consisting of a mixture of anionic andnonionic surfactants which are solid at storage conditions wherein saidanionic surfactant is present in the amount of from about 60 to about95%/wt., based on the weight of said mixture of anionic and nonionicsurfactants, said granules having been prepared by premixing saidmixture of surfactants and said bleach activator, homogenizing theresulting mixture to form a paste which is extrudable in strand form,extruding said paste under elevated pressure at a temperature of up to90° C., cutting the extrudate into granules, and rounding said granulesunder conditions which prevent said granules from sticking together. 2.A composition prepared as in claim 1 wherein said mixture of surfactantsand said bleach activator is substantially anhydrous.
 3. A compositionprepared as in claim 1 wherein no water is added thereto.
 4. Acomposition prepared as in claim 1 including adding a colorant and fromabout 0.1 to about 0.5%/wt. of water, based on the weight of said bleachactivator, to said mixture of surfactants before premixing it with saidbleach activator.
 5. A composition prepared as in claim 1 wherein saidmixture of surfactants is at least partly liquid at the granulationtemperature of said composition.
 6. A composition prepared as in claim 1wherein said mixture of surfactants is partly liquid and partly solid atthe granulation temperature of said composition.
 7. A compositionprepared as in claim 1 wherein said nonionic surfactant comprises a C₁₂-C₁₈ fatty alcohol ethoxylate having an average ethylene oxide molecontent of up to about
 10. 8. A composition prepared as in claim 1having an apparent density of at least about 500 g./l.
 9. A compositionprepared as in claim 1 wherein said mixture of surfactants and saidbleach activator is homogenized and extruded in a pellet press having apressure roller which is maintained at a predetermined workingtemperature of up to about 90° C.
 10. A composition prepared as in claim9 wherein said working temperature is from about 45° C. to about 70° C.11. The process of preparing free-flowing granules containing from about70 to about 95% by weight of a bleach activator, based on the weight ofsaid granules, and a substantially water-free binder for said bleachactivator, said binder consisting of a mixture of anionic and nonionicsurfactants which are solid at storage conditions wherein said anionicsurfactant is present in the amount of from about 60 to about 95% byweight, based on the weight of said mixture of anionic and nonionicsurfactants, said process consisting essentially of premixing saidmixture of said anionic and nonionic surfactants and said bleachactivator, homogenizing the resulting mixture to form a paste which isextrudable in strand form, extruding said paste under elevated pressureat a temperature of up to 90° C., cutting the extrudate into granules,and rounding said granules under conditions which prevent said granulesfrom sticking together.
 12. A process as in claim 11 wherein saidmixture of surfactants and said bleach activator is substantiallyanhydrous.
 13. A process as in claim 11 wherein no water is added tosaid composition.
 14. A process as in claim 11 including adding acolorant and from about 0.1 to about 0.5%/wt. of water, based on theweight of said bleach activator, to said mixture of surfactants beforepremixing it with said bleach activator.
 15. A process as in claim 11wherein said mixture of surfactants is at least partly liquid at thegranulation temperature of said composition.
 16. A process as in claim11 wherein said mixture of surfactants is partly liquid and partly solidat the granulation temperature of said composition.
 17. A process as inclaim 11 wherein said nonionic surfactant comprises a C₁₂ -C₁₈ fattyalcohol ethoxylate having an average ethylene oxide mole content of upto about
 10. 18. A process as in claim 11 wherein said granules have anapparent density of at least about 500 g./l.
 19. A process as in claim11 including homogenizing and extruding said mixture of surfactants andsaid bleach activator in a pellet press having a pressure roller whichis maintained at a predetermined working temperature of up to about 90°C.
 20. A process as in claim 19 wherein said working temperature is fromabout 45° C. to about 70° C.